A husband was trying to prove

A husband was trying to prove to his wife that women talk more than men. 
He showed her a study which indicated that men use about 10,000 words per day, whereas women use 20,000 words per day. 
His wife thought about this for a while. 
She then told her husband that women use twice as many words as men because they have to repeat everything they say. 
Her husband looked stunned. He said "What?"